A number of pressing problems confront the healthcare industry. As of June 2012 the United Network for Organ Sharing (UNOS) had 114,636 patients registered as needing an organ transplant. According to UNOS, between January and March 2012 only 6,838 transplants were performed. Each year more patients are added to the UNOS list than transplants are performed, resulting in a net increase in the number of patients waiting for a transplant.
This has placed an economic burden on the US healthcare economy both in direct and indirect costs. Organ transplant and regenerative medicine are expected to eventually meet the challenge of replacement and regeneration as the portfolio of biomaterials increases. In the past 50 years, scientists have been limited in the choice of biomaterials useful in tissue/organ engineering.
One new biomaterial, poly(glycerol sebacate), was developed for tissue engineering and has expanded into therapeutic areas including drug delivery, orthopedics, cardiovascular, neurovascular and soft tissue repair. With benefits such as little to no fibrous capsule formation, antimicrobial activity, non-immunogenicity, among others, the material is desirable for implantable as well as topical applications. Current forms of this biomaterial, however, have some limitations on its ability to be manipulated into various forms for specific applications.
Additive manufacturing has become an important tissue scaffold fabrication tool in tissue engineering and regenerative medicine. Precise patient specific 3-D tissue scaffold constructs when designed by software imported from such 3-D medical diagnostic imaging modalities as MRI and ultrasound, can reconstruct in vitro and in vivo tissue framework (tissue scaffold) from subject tissue.
There is a serious limitation to the choice of biocompatible and resorbable polymer technologies to build the basic compositions supporting scaffold structures by additive manufacturing. Historically, lactide and glycolide polymers have been the resorbable polymers of choice. While the basic chemistry is resorbable, the question of biocompatibility has been challenged. Once in the wound space, lactide and glycolide polymers break down, releasing highly acidic by-products which extend the healing period, adversely impact the immune system, and form scar tissue, disrupting the return of native function.